The invention concerns a collimator for defining a beam of high energy radiation which is emitted from a substantially punctiform radiation source and directed onto an object to be treated for, in particular, stereotactic conformation radiation of tumors, wherein the collimator is designed to scan an irregular object to be treated with beams which are defined by a collimator opening.
Collimators are used for conform and high-dosed radiation of target volumes having complicated shapes. There are various conventional types of collimators which usually require large amounts of time and/or great technical effort to obtain high accuracy, in particular exact definition of the radiation fields.
Compensators are particularly time-consuming, since a shaped collimator must be produced for each surface to be irradiated, and the shaped collimators on the radiation devices must be changed when changing the individual irradiation directions.
To reduce this time, multi-leaf collimators are normally used. DE 199 05 823 C1 discloses an example of such a collimator. The shaping is thereby obtained using a plurality of collimator sheets (leafs), with each leaf having a motor, a path detector, and a control for the orientation of the front edge of the leaf in accordance with the path of the rays. This effort is required for a total of between 80 and 120 leaves, wherein the leaves must be adjusted for each surface to be irradiated and for generating different radiation intensities.